"Whatever we do when we get extraordinary rains like we had recently, no amount of engineering can prevent flooding... unless you want to lose half the roads and have canals." (Channel News Asia, 21 July 2010) - Mr Lee Kuan Yew, Minister Mentor
I tend to disagree and would like to suggest two alternative approaches.
One approach is to build pumps and underground pipes to channel rainwater from canals and monsoon-drains in flood-prone areas to other canals or into the reservoirs. This redistribution can prevent overflowing of rainwater and ultimately curb the flooding.
This system has been proven to be effective in China. This is reported in The Epoch Times in Hong Kong on 28 July 2010. As quoted from the article titled “Ancient Chinese drain system saves city from flooding” - “..some experts estimate the system can handle additional three or four times the current rainwater”.
This approach can be adapted to Singapore by constructing underground pipes to channel water from the Bukit Timah Canal to the Catchment Area around MacRitchie and Lower Peirce Reservoir to prevent floods along Coronation Road and Bukit Timah Road. If this is successful, we can also channel rain water from the Stamford Canal to the Bukit Timah Canal, to prevent future floods in the Orchard Road area.
Another approach is to build dams. Dams have been known to help prevent floods. A notable example is the Three Gorges Dam in China’s Hubei province. Why not build dams on a smaller scale across our canals and monsoon-drains in critical areas prone to flooding?
For instance, dams can be built at various sections along the drains and canals that carry water into Stamford Canal. These dams will be able to hold back rain water, thus preventing water from gushing into the Stamford Canal and causing flash floods along Orchard Road. These dams can also trap debris before it is washed down into the Stamford Canal. To prevent stagnant water and mosquito breeding, there can also be a hole at the bottom of the dam.